The mentioned MSEP formulations are then utilized in conjunction with different optimization techniques to develop diverse precoding algorithms. First, projection based methods (PBMs) are considered as practical precoding techniques. PBM is a popular class of approaches present in literature, many works have utilized PBMs to devise practical precoding algorithms, e.g. [1]}, [2]}, [3]}, [4]}, [5]}, [6]}. Then MSEP B&B approaches are considered for the computation of the optimal precoding vector. The proposed B&B algorithms differ from the ones present in literature, e.g. [7]}, [8]}, [9]}, [3]}, in terms of using a more restrictive pruning step which, then, contributes to a decreased average number of evaluated bounds and also in terms of the flexibility for choosing the projection step.
